Metro said Friday that it believes an electrical short between two rail cars was part of the problem that lead to doors unexpectedly opening Tuesday on two rail cars as the train was moving.

On Friday, Metro said the transit agency’s investigation team had replicated the incident in a rail yard and found that there was a “misalignment of the contact head that transfers information between two cars.” That created an electrical short and caused the door to open, Metro officials said.

(Michael S. Williamson/The Washington Post)

One commuters’s account to The Washington Post of what happened provided new details about the potentially deadly malfunction.

Kimberly Morgan of Takoma Park wrote in an e-mail that she was riding on a Red Line train headed to Shady Grove Tuesday morning when the doors opened just outside of the Takoma station.

She wrote that “all three sets of doors opened on the train while it was moving.”

“Fortunately, the train was not crowded, and no one was leaning against the doors,” she wrote. “The train stopped, the doors opened and closed a few times, and then we proceeded a few more stations until someone came on to ask us to move to another car on the train.”

She said she noticed “after that how commonly people lean against the doors, and how someone could have been killed.”

Metro chief spokesman Dan Stessel said Friday that a technician had “boarded the train for something other than a door problem at Fort Totten and was told by customers that there was a door issue.”

The technician, he said, took the rail car where customers said there was a door problem out of service and directed customers to go to another rail car. The technician stayed on for several stops, Stessel said.

But later, the doors on that same rail car and on another one next to it opened unexpectedly while the train was moving between Tenleytown and Van Ness stations.

A passenger aboard the train took a picture of it, and it was posted to Unsuck DC Metro.

Metro said there were no reported injuries.

Stessel said the train operator called Metro’s command center, and car maintenance personnel were sent to meet the train at the Tenleytown stop. The train was off-loaded and taken to a rail yard for “diagnostic testing,” he said.

He said such incidents of doors opening unexpectedly when trains are moving are “extremely, extremely rare.” He said it had been “multiple years” since a similar incident had happened.

The two rail cars are part of Metro’s 1000 series which were involved in a deadly crash in 2009 on the Red Line and are expected to be replaced soon with new rail cars.

In Tuesday’s incident the doors opened on the two 1000 series rail cars, which were attached to a set of 5000 series rail car on one end.

Metro’s review found that “the fail-safe features of the train worked as designed, automatically applying the brakes to bring the train to a stop when the events occurred,” Metro said.

On Friday afternoon, Metro said it will begin to inspect all 5000 series rail cars for similar issues and it will do a fleet-wide inspection in about two weeks. It is still looking into the root cause of the door opening issue.

Metro has had chronic problems with doors on rail cars. About two-thirds of train delays involve troubles with doors, Metro officials recently told board members.

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